var q cobolprogramtofindsumofnnumbersFor loop Wikipedia. In computer science, a for loop or simply for loop is a control flowstatement for specifying iteration, which allows code to be executed repeatedly. The syntax of a for loop is based on the heritage of the language and the prior programming languages it borrowed from, so programming languages that are descendants of or offshoots of a language that originally provided an iterator will often use the same keyword to name an iterator, e. ALGOL use for, while descendants of Fortran use do. There are other possibilities, for example COBOL which uses PERFORM VARYING. Unlike many other kinds of loops, such as the while loop, the for loop is often distinguished by an explicit loop counter or loop variable. This allows the body of the for loop the code that is being repeatedly executed to know about the sequencing of each iteration. For loops are also typically used when the number of iterations is known before entering the loop. For loops are the shorthand way to make loops when the number of iterations is known, as every for loop could be written as a while loop. The name for loop comes from the English word for, which is used as the keyword in most programming languages to introduce a for loop. The term in English dates to ALGOL 5. ALGOL 6. 0 it is the direct translation of the earlier German fr, used in Superplan 1. Heinz Rutishauser, who also was involved in defining ALGOL 5. ALGOL 6. 0. The loop body is executed for the given values of the loop variable, though this is more explicit in the ALGOL version of the statement, in which a list of possible values andor increments can be specified. In FORTRAN and PLI though, the keyword DO is used and it is called a do loop, but it is otherwise identical to the for loop described here and is not to be confused with the do while loop. For loop illustration, from i0 to i2, resulting in data. A for loop statement is available in most imperative programming languages. Even ignoring minor differences in syntax there are many differences in how these statements work and the level of expressiveness they support. Generally, for loops fall into one of the following categories Traditional for loopseditThe for loop of languages like ALGOL, Simula, BASIC, Pascal, Modula, Oberon, Ada, Matlab, Ocaml, F, and so on, requires a control variable with start and end values and looks something like this forifirsttolastdostatement or just forifirst. Depending on the language, an explicit assignment sign may be used in place of the equal sign and some languages require the word in even in the numerical case. The DIVISION declares the platform on which COBOL Program is tested and run. It also declares the InputOutput files for the program. Overview Translations Belarussian, Bulgarian, Russian, SerboCroatian, Slovakian Ukrainian cloc counts blank lines, comment lines, and physical lines of source. COBOL Mainframe forum Mainframe Mainframe IBM tutorial, tutorials, material, materilas, faq, faqs, interview questions, COBOL,CICS,DB2,JCL,IMS DB, IMS DC, REXX. In computer science, a forloop or simply for loop is a control flow statement for specifying iteration, which allows code to be executed repeatedly. Awk, C, C, E, merd, PHP5, Python, Ruby, Tcl, YCP lt Python Haskell Oz Classic REXX, Prolog Ada Maple, XPath lt Beta, F, OCaml. An optional step value an increment or decrement 1 may also be included, although the exact syntaxes used for this differs a bit more between the languages. Some languages require a separate declaration of the control variable, some do not. Another form was popularized by the C programming language. It requires 3 parts the initialization, the condition, and the afterthought and all these three parts are optional. 1forINITIALIZATION CONDITION AFTERTHOUGHT Code for the for loops body goes here. The initialization declares and perhaps assigns to any variables required. The type of a variable should be same if you are using multiple variables in initialization part. The condition checks a condition, and quits the loop if false. The afterthought is performed exactly once every time the loop ends and then repeats. Here is an example of the traditional for loop in Java. Prints the numbers 0 to 9. System. out. printi System. System. out. println Iterator based for loopseditThis type of for loop is a generalisation of the numeric range type of for loop, as it allows for the enumeration of sets of items other than number sequences. It is usually characterized by the use of an implicit or explicit iterator, in which the loop variable takes on each of the values in a sequence or other data collection. A representative example in Python is foriteminsomeiterableobject do. Somethingdo. Something. Else. Where someiterableobject is either a data collection that supports implicit iteration like a list of employees names, or may in fact be an iterator itself. Some languages have this in addition to another for loop syntax notably, PHP has this type of loop under the name for each, as well as a three expression for loop see below under the name for. Vectorised for loopseditSome languages offer a for loop that acts as if processing all iterations in parallel, such as the for all keyword in FORTRAN 9. For example, in the for statement in the following pseudocode fragment, when calculating the new value for Ai, except for the first with i 2 the reference to Ai 1 will obtain the new value that had been placed there in the previous step. In the for all version, however, each calculation refers only to the original, unaltered A. N 1 do Ai Ai 1 Ai Ai 1 3 next i. N 1 do Ai Ai 1 Ai Ai 1 3. The difference may be significant. Some languages such as FORTRAN 9. PLI also offer array assignment statements, that enable many for loops to be omitted. Thus pseudocode such as A  0 would set all elements of array A to zero, no matter its size or dimensionality. The example loop could be rendered as. A2 N 1 A1 N 2A2 N 1A3 N3 But whether that would be rendered in the style of the for loop or the for all loop or something else may not be clearly described in the compiler manual. Compound for loopseditIntroduced with ALGOL 6. PLI, this allows the iteration of a loop to be compounded with a test, as in. N while Ai 0 do etc. That is, a value is assigned to the loop variable i and only if the while expression is true will the loop body be executed. If the result were false the for loops execution stops short. Granted that the loop variables value is defined after the termination of the loop, then the above statement will find the first non positive element in array A and if no such, its value will be N 1, or, with suitable variations, the first non blank character in a string, and so on. Loop counterseditIn computer programming a loop counter is the variable that controls the iterations of a loop a computer programming language construct. It is so named because most uses of this construct result in the variable taking on a range of integer values in some orderly sequences example., starting at 0 and end at 1. Loop counters change with each iteration of a loop, providing a unique value for each individual iteration. The loop counter is used to decide when the loop should terminate and for the program flow to continue to the next instruction after the loop. A common identifier naming convention is for the loop counter to use the variable names i, j, and k and so on if needed, where i would be the most outer loop, j the next inner loop, etc. The reverse order is also used by some programmers. This style is generally agreed to have originated from the early programming of FORTRANcitation needed, where these variable names beginning with these letters were implicitly declared as having an integer type, and so were obvious choices for loop counters that were only temporarily required. The practice dates back further to mathematical notation where indices for sums and multiplications are often i, j, etc. Programming Interview Questions Geek.